The present invention relates generally to light sources and, more particularly, to apparatus for providing light which is non-toxic to human eyes.
In order to perform ophthalmic surgery, adequate illumination of the eye is required. Such illumination is not adequately provided by a focused lamp located above the surgical area because the surgical field is within the eye. Rather, a beam of light is usually delivered to the surgical area with a fiber optic cable.
The quality of the light delivered to the surgical area is very important. In order to provide high clarity and vision in an anterior or posterior segment of the eye, it is preferred to deliver a bright, white light to the surgical area. The white light preferably does not include any hues which could make it difficult to distinguish areas within the eye. Typical light sources used in ophthalmic surgery have a correlated color temperature of about 3200.degree. K (Kelvin). In contrast, sunlight, the standard for white light, has a color temperature of about 6800.degree. K. Such low color temperature lamps are used to avoid light toxicity to the eye. However, such low color temperature lamps do not provide a balanced white light, but rather the light includes red, orange or even yellow hues. The inclusion of such hues makes it difficult to view the retinal surface because a high percentage of the surface area of the retina is red. A light which includes a red hue brings out the red tissue of the skin, thereby making it harder to see subtle differences inside the eye. That is, visibility of the natural colors of the illuminated tissue is important for diagnostic purposes, and a color tinted light exacerbates the surgeon's ability to see the work area. Accordingly, it would be desirable to deliver a safe white light to a surgical area of the eye.
Unfortunately, it is difficult to deliver light without any darkened regions and/or dark rings. Thus, it would also be advantageous to deliver the light with a uniform or homogeneous distribution.